1. Field of the Invention
The invention pertains to means for exciting pulsed lasers. More particularly, the invention pertains to a method and means for extending the duration of the lasing action within a laser by sequentially exciting different portions of the laser gain medium.
2. Description of the Prior Art
A principal factor limiting the maximum output pulse length that can be obtained from a pulsed laser is the maximum time the laser gain medium can remain excited so that it has optical gain.
For example, for many types of laser gain media, the output pulse length is limited because quenching phenomena prevent the gain medium from remaining excited so as to have optical gain for more than a limited period of time, even if one attempts to pump the gain medium for a longer time period.
Also, a pulsed gas discharge laser has a limited output pulse length for an additional reason. In this type of laser, the gaseous gain medium is excited by an electric glow discharge in the gas. The duration of the excitation is limited because, after a certain period of time, the glow discharge will break down into arcs of high current density which do not effectively excite the gain medium.